Hitches have long been used to provide a mechanism for connecting a trailer to a towing vehicle. Such hitches, especially when used to connect a trailer to a motor vehicle, are typically detachable from the towing vehicle.
Hitches are made detachable from the towing vehicle to solve the following dilemma. It is useful for a hitch to extend beyond the rear of the towing vehicle to facilitate attachment of the trailer to the hitch, and to allow the trailer to pivot freely relative to the towing vehicle.
A hitch is commonly attached to the towing vehicle by means of a rigid square or rectangular sleeve which is fixedly mounted at the rear of the vehicle. The corresponding square or rectangular member of the hitch, which is slightly smaller than the sleeve, is inserted into the sleeve. A locking device, such as a pin, a bolt or any other suitable element, is then inserted transversally through matching holes in the side walls of the sleeve and the member, and is then locked with a locking device, typically via a cotter pin, to prevent the locking device from slipping out of the holes.
Some space is usually left between the inner walls of the sleeve and the outer walls of the member to allow easy attachment and detachment of the hitch. For the same reason, space is usually left between the locking device and the holes in the walls of the member and sleeve. These spaces are large enough to allow for ease of coupling and decoupling of the hitch despite imperfections in the machining of the hitch and sleeve and despite rust and other surface accumulations (e.g. ice, mud, dirt, dust, etc.).
The problem with these spaces is that they allow play in the connection between the hitch and the sleeve that can be noisy, more particularly when carrying an empty trailer. The play between the outer walls of the hitch and the inner walls sleeve can cause clanging noises and vibrations that can be felt within the towing vehicle. That play may also be magnified by the lever arm of the hitch so that it is felt more strongly by the trailer. The play between the locking device and the holes in the walls of the member and sleeve can be felt mainly in the acceleration and deceleration of the trailer relative to the towing vehicle.
Prior art discloses systems wherein the outer walls of the member of the hitch are pressed against the inner walls of the sleeve. This configuration decrease the level of vibration and noise but it presents an inconvenient. Some users can forget to install the locking device to lock the hitch in the sleeve. The installation of the locking device may be forgotten since the member is press fitted in the sleeve of the vehicle and may seem to be secured. Consequently, when the vehicle is in use, there is a high risk that the hitch will come out from the sleeve, principally because of the vibration of the vehicle.
For the aforementioned reasons, there is clearly a need for an improved hitch wherein the shortcomings of prior art hitches are at least mitigated.